Winds of change blow for offshore power operators

Lynn and Inner Dowsing wind farm, off the Lincolnshire coast. Windier weather will make windfarms in East Anglia and the south-east more economic. Photograph: David Sillitoe /Guardian

It's official: it's getting windier down south. This unexpected quirk of climate change has given a much needed boost to offshore wind-farm developers.

For those struggling to make the economics of hugely expensive wind farms work, more wind equals more money.

Experts said that the waters off the coast of East Anglia and Essex could host many more wind farms as a result.

The research, from Atmos Consulting, has found that wind speeds in these areas have been rising so much that wind farms could generate 50% more electricity than envisaged a decade ago.

More than 10GW of offshore wind projects - enough to power 10m homes - being planned for the southern part of the North Sea could benefit.

Based on information taken from Nasa satellite images, the research found that average annual wind speed in the southern part of the North Sea had increased from about 7.5 metres per second in 1990 to 8.5 metres in 2008. In contrast, wind speeds in the northern part of the North Sea, off the coast of Scotland, have remained constant during this period.

If these trends continue, in a decade the south could be windier all year round than northern areas and double the power generated by wind farms off the coast of East Anglia and Essex.

The news could rescue the £3bn London Array wind-farm project planned in the Thames estuary. Project developer E.ON has warned that the economics of the project are on a "knife edge" and will make a final decision this summer.

Atmos Consulting has developed software to process 22 years of satellite images from space agency Nasa. These images measure the size of small, capillary waves on the ocean surface, which indicate the strength of the wind.

Until now, developers have relied on wind-speed levels taken on oil and gas installations or have used meteorological masts planted offshore. The Met Office has only limited satellite data to track offshore wind speeds in the North Sea but is working with wind-farm developers to produce a comprehensive set of data of the last 30 years. A spokeswoman admitted it would take two years to develop.

Duncan Ayling, head of offshore renewables at the British Wind Energy Association, said: "There have been wind-speed measurements on oil and gas installations that give some localised historic data, but a lot of the rest of it is extrapolation. If this technology provides an accurate measurement, it would be very exciting. More wind equals more money for projects. It would enable wind-farm developers to more accurately forecast revenues and have more certainty about the expected return on their investment."